The deployment of advanced high bit-rate mobile networks has opened up new opportunities for delivering a host of services in a way that was not possible with earlier second generation wireless networks. Recent systems including third generation (3G) systems, such as those specified for use with the Global System for Mobile Communications (GSM) wireless standard, enable the delivery of new digital services such as video calls and the playback of multimedia applications that are comprised of audio and video clips. In this regard, the increased bit rates of 3G systems widen the possibilities for providing digital services.
The increased bit rates of 3G systems provide adequate performance for delivering high quality digital audio and acceptable quality moving image clips. However, at these transfer rates it may be difficult to handle exceedingly high data intensive tasks such as delivering high quality full-motion video and transferring very large data files to mobile terminals. In this regard, attempts at downloading large data files may lead to inconveniently long downloading times that can be undesirably costly for users. For this and other reasons, alternative broadband delivery techniques have been investigated that could provide a practical solution for high data intensive tasks in terms of lower cost and convenience for the users involved.
One such delivery technique that has shown promise is Digital Video Broadcasting (DVB). In this regard, DVB-T, which is related to DVB-C (cable) and DVB-S (satellite), is the terrestrial variant of the DVB standard. As is well known, DVB-T is a wireless point-to-multipoint data delivery mechanism developed for digital TV broadcasting, and is based on the MPEG-2 transport stream for the transmission of video and synchronized audio. DVB-T has the capability of efficiently transmitting large amounts of data over a broadcast channel to a high number of users at a lower cost, when compared to data transmission through mobile telecommunication networks using, e.g., 3G systems. Advantageously, DVB-T has also proven to be exceptionally robust in that it provides increased performance in geographic conditions that would normally affect other types of transmissions, such as the rapid changes of reception conditions, and hilly and mountainous terrain. On the other hand, DVB-H (handheld), which is also related to DVB-T, can provide such increased performance particularly for wireless data delivery to handheld devices.
Digital broadband data broadcast networks are known. As mentioned, an example of such a network enjoying popularity in Europe and elsewhere world-wide is DVB which, in addition to the delivery of television content, is capable of delivering data, such as Internet Protocol (IP) data. Other examples of broadband data broadcast networks include Japanese Terrestrial Integrated Service Digital Broadcasting (ISDB-T), Digital Audio Broadcasting (DAB), and MBMS, and those networks provided by the Advanced Television Systems Committee (ATSC). In many such systems, a containerization technique is utilized in which content for transmission is placed into MPEG-2 packets which act as data containers. Thus, the containers can be utilized to transport any suitably digitized data including, but not limited to High Definition TV, multiple channel Standard definition TV (PAUNTSC or SECAM) and, of course, broadband multimedia data and interactive services.
The combined use of mobile telecommunications with a broadband delivery technique such as DVB-T has been proposed in the past in order to achieve efficient delivery of digital services to users on the move. This would take advantage of existing infrastructures in the effort to provide personal communications (already prevalent) and the growing demand for Internet access, together with the expected rise of digital broadcasting, so that users can receive these services with a single device. Furthermore, DVB-T is a cross platform standard that is shared by many countries thereby making frequency compatibility and roaming less of an issue. The combination of mobile telecommunication and relatively very low cost digital broadband delivery techniques provides the possibility of interactive services such as uni-directional and bi-directional services such as audio and video streaming (e.g., TV, radio, etc.), file downloads and advanced gaming applications, etc.
It is contemplated that digital broadband data broadcast networks will be used to broadcast content for one or more television, radio and/or data channels. For example, it is contemplated that mobile television DVB-H broadcasts will include content for 10-50 or more television channels. In various instances, such content is broadcast in bursts each of which includes time-sliced content for a plurality of channels. This broadcasting of channels in time slices achieves power saving in mobile devices by permitting such devices to power up to receive a burst of time-sliced content for a number of channels, and then power down for the typically longer time period between bursts.
As will be appreciated, when a plurality of available channels of content are broadcast, the user may desire to browse through the available channels to select a desired channel to receive and consume (e.g., display, play, etc.). Such browsing, often referred to as “channel hopping,” generally includes the user moving from one channel to the next one by one, selecting each channel so that the user briefly receives content for the selected channel until the moving on to the next channel. By briefly receiving content for a selected channel, the user can assess the received content, and decide to either continue to receive that content (ceasing to channel hop), or move on to the next channel.
As will also be appreciated, because channels may be broadcast in bursts that include time-sliced content for those channels, users moving from one channel to the next may experience a time delay (i.e., channel tuning time) dependent upon the burst interval as well as a number of other delays. Undesirably, such time delays can last up to ten seconds or more. To decrease this time delay, however, techniques have been developed to buffer content for channels on either side of the currently selected channel into memory of the user device. In accordance with such techniques, then, users receive content for three channels, as opposed to one channel, with one channel of content being consumed and the other two being buffered in memory. Thus, if the user moves on to the next channel, that channel's content can initially be pulled from the buffer memory to avoid the time delay of waiting until the next burst interval to receive its content. But while such buffering may reduce the delay associated with channel hopping from one channel to the next, it also reduces the power saving benefits of broadcasting channels in time-sliced bursts, and may not even be possible to fully achieve with current receiver performance.